As a dog owner who used to live in NYC, I can tell you it's a very, very easy place to have a dog. Lots and lots of places to stay, eat, shop, etc., so no worries.  

·         Hotel Sofitel New York will let you come with anything short of a cheetah

·         The Benjamin Hotelis very well known as a super-dog friendly hotel that even has an in-house dog psychic

·         The Carlyle - most places in NY are great for people watching--this is good for people and dog watching. I can almost promise you you'll see some celebrity dogs here. 

·         Barking Dog Luncheonette (restaurant)

·         Both Pastis on 9th ave. and  Porto-Bello Restaurant downtown (I forget what street) will let you sit outside with your dog. A lot of restaurants in NYC will let you do that, actually.

·        Biscuits and Bath has a lot of locations and they are pretty well regarded in the city. They have just about every kind of service for your dog you can imagine including a way to see them on video.

Agree with Courtney, people in Manhattan LOVE dogs (whether they own them or not) and there are also tons of beautiful parks you can take your dog so you can enjoy nature while letting your dog have some fresh air -- here are a few!

• Carl Schurz Dog Run on the Upper East Side has 2 dog runs - one for large dogs and small dogs / puppies. You can also walk your dog along the river or go for a run
• Madison Square Park has a small dog run where you can take your dog and then when finished, take pictures at the Flatiron Building or stroll down 5th Avenue
• Central Park doesn't have any enclosed/fenced in dog runs but has over 20 areas where you can let your dog off leash